import java.awt.*;
import java.applet.*;
import java.awt.event.*;

/**
 * This application provides a GUI to operate a hotel reservation system
 *
 * @author Ting Shih
 * @version 1.0.0
 */
public class HotelReservation extends Frame
	implements ActionListener, WindowListener  {

	private TextField input, output;
	private Panel opsPad;
	private Checkbox reserveBox;
	private Checkbox cancelBox;
	private CheckboxGroup ops;
	private Button start;

	private Reservation resv;

	/**
	 * The main routine.
	 *
	 * @param args  String arguments.  Not used.
	 */
	public static void main (String[] args) {

		HotelReservation sc = new HotelReservation(550, 100);
		sc.show();
	}

	/**
	 * Initializes widgets and creates layouts.
	 * 
	 * @param width  the width of the window
	 * @param height  the height of the window
	 */
	public HotelReservation(int width, int height)  {
	
		super("Hotel Reservation");
		setSize (width, height);

		input = new TextField(15);
		output = new TextField(30);

		opsPad = new Panel();
		opsPad.setLayout(new GridLayout(2,1));


		CheckboxGroup ops = new CheckboxGroup();

		reserveBox = new Checkbox("Reserve", ops, true);
		cancelBox = new Checkbox("Cancel", ops, false);
	
		opsPad.add(reserveBox);
		opsPad.add(cancelBox);
	
		start = new Button("Start");
	
		setLayout(new FlowLayout());
		add(input);
		add(opsPad);
		add(start);
		add(output);
	
		resv = new Reservation();
	
		start.addActionListener(this);
		addWindowListener(this);
	}

	private void reserve(String customer)  {
	
		if (resv.reserve (customer)) {
			output.setText("Reservation has been made for " + customer + ".");
		} else {
			output.setText ("The hotel is full.");
		}
		input.setText("");
	}

	private void cancel(String customer)  {

		if (resv.cancel (customer)) {
			output.setText("Reservation has been canceled for " + customer + ".");
		} else {
			 output.setText (customer + " has no reservation at this hotel.");
		}
		input.setText("");
	}

	/**
	 * Process the button events.
	 *
	 * @param e  the event generated.
	 */
	public void actionPerformed(ActionEvent evt)  {

		if (evt.getSource().equals(start))  {
			if (reserveBox.getState())  {
				reserve(input.getText());
			} else {
				cancel(input.getText());
			}
		}
	}
	
	/**
	 * method contains empty body
	 *
	 * @param e  not used
	 */
	public void  windowActivated(WindowEvent  e)  {}

	/**
	 * method contains empty body
	 *
	 * @param e  not used
	 */
	public void  windowClosed(WindowEvent  e)  {}

	/**
	 * When the close box is clicked or the close window menu item
	 * is chosen, this method causes the application to terminate
	 *
	 * @param e  not used
	 */
	public void  windowClosing(WindowEvent  e)  {
		
		setVisible(false);
		dispose();
		System.exit(0);
	}

	/**
	 * method contains empty body
	 *
	 * @param e  not used
	 */
	public void  windowDeactivated(WindowEvent  e)  {}

	/**
	 * method contains empty body
	 *
	 * @param e  not used
	 */
	public void  windowDeiconified(WindowEvent  e)  {}

	/**
	 * method contains empty body
	 *
	 * @param e  not used
	 */
	public void  windowIconified(WindowEvent  e)  {}

	/**
	 * method contains empty body
	 *
	 * @param e  not used
	 */
	public void  windowOpened(WindowEvent  e)  {}
}

import java.util.*;

/**
 * This class models a hotel reesrvation system
 *
 * @author Ting Shih
 * @version 1.0.0
 */
public class Reservation {

	/*
	 * occupancy is an array that indicates the occupant of each room.  
	 * If there are no occupants, it is marked null
	 */
	private String[] occupancy;

	/* MAX_ROOMS is the maximum number of rooms.and also represent the array size */
	private int MAX_ROOMS = 5;

	/**
	 * Creates a list of rooms and make them available (by setting them to null).
	 */
	public Reservation()  {

		/* creates the array of occupancy for the size of MAX_ROOMS */
		occupancy = new String[MAX_ROOMS];

		/* 
		 * The following is not necessary, since a newly constructed array
		 * will have null values by default. But we will set them to null
		 * for illustrative purposes.
		 */
		for (int index = 0; index < occupancy.length; index++)  {
			occupancy[index] = null;
		}
	}

	/**
	 * Adds a new customer to the hotel.
	 * 
	 * @param customer is the name of the customer to be added.
	 * @return true if the hotel is not full and reservatoin was made successfully,
	 *         false otherwise.
	 */
	public boolean reserve (String customer)  {

		int roomChecked = 0; 
	
		/* Use a while-loop to check if a room is available */
		while (roomChecked < occupancy.length && occupancy[roomChecked] != null )  {
			roomChecked ++; 
		}

		/*
		 * if roomChecked is is less than the number of rooms in the hotel, 
		 * then there is an availability in the hotel, otherwise, all the rooms 
		 * have been searched and no availability was found 
		 */
		if (roomChecked < occupancy.length)  {
			occupancy[roomChecked] = customer;
			return true;
		} else {
			return false;
		}
	}

	/** 
	 * checks out a customer and marks the room as empty
	 *
	 * @param customer is the name of the customer checking out
	 * @return true if customer had a prior reservation so cancellation possible,
	 *         false otherwise.
	 */
	public boolean cancel (String customer)  {

		int roomChecked = 0;

		/* searches all the rooms until the customer who had a reservation is found */
		while (roomChecked < occupancy.length && 
			(occupancy[roomChecked] == null || !occupancy[roomChecked].equals(customer)) )  {		
			roomChecked++; 
		}
	
		/* 
		 * system cancels the reservation made by marking the room available
		 * otherwise return false to indicate the customer did not make a reservation
		 */
		if (roomChecked < occupancy.length)  {
			occupancy[roomChecked] = null;  
	 		return true;
		} else {
			return false;
		}
	}

}